Frehley and Criss did well despite the mistreatment and purposely being unacknowledged, earning fortunes anyway due to the massive amount of money KISS earned over the years as an entity, enterprise and cultural phenomenon. The four solo album project was meant to prove that the founders' popularity far outstripped that of "the help" - and it hilariously blew up in Simmons' and Stanley's faces.
Ace was never the greatest guitarist nor known for innovation like Clapton or Page, but he was a trooper who dutifully played thousands of shows in uncomfortable make-up and costumes; often risking injury due to pyrotechnics, stunts and the vices that plague rock stardom. Thank you, sir.
If you only know his work from his time with KISS please listen to this instrumental, "Fractured Mirror", from that solo album.
(Truly great astronomy photographs in the video for you cosmological compatriots.)